Marine Arthropods and Paleontology

Scientists have found evidence of a complex brain in a fossil arthropod that’s estimated to be 520 million years old. This extinct crustacean’s brain supports some scientists’ hypothesis that once a basic brain evolved, it changed little.

In 2021 scientists found a fossilized brain of a horseshoe crab showing that the brains have not changed much in 300 million years. A crab found in amber "tells us that crabs have conquered land and freshwater more than 12 times independently!"

A giant shrimp called Anomalocaris is one of the most well-known of the fossils from the Cambrian. Read our Featured Creature about the ancient animal.

Trilobites once were the dominant species in the marine environment. They ranged in size from a quarter inch to dinner plate size and had complex behaviors. The number of trilobites decreased in the end of the Paleozoic and vanished in the end-Permian extinction. As predators evolved, so did the complexity of trilobite defenses and their eyes. Scientists found a fossil trilobite with tiny eyes inside its eyes.

General Info

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    Book with pencil

Role in Ecosystem

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    Bee with arrows around it


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    Thermometer and waves

Human Interaction

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    Human next to globe


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    Skull of dinosaur
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    Lesson Plan
    Marine Arthropod Adaptations + Engineering Design
    Students explore the diversity and adaptations of marine arthropods.

    Full Lesson Plan